Question

Factorise the following expression.

121b² − 88bc + 16c²

Answer 1

121b² − 88bc + 16c²

On writing it as follows:

(11b)² − 2 × 11b × 4c + (4c)²

Using the identity a² − 2ab + b² = (a − b)²

= (11b − 4c)² 

= (11b − 4c) (11b − 4c)